It seems odd that anyone would take a dock so seriously that a heated discussion would fire up on twitter over something so apparently modest. Think about it though: for those of us that work at our computers for seven, eight or more hours every day, this is your working environment. It is as crucial to a healthy desk as your seating comfort and observance of healthy use practices. You're going to interact with elements on the screen countless times and therefore it needs to be just right for you.
Details are never trivial, they just vary in priority from person to person.
As it happens, I love the dock in it's standard position because I think it's fairly aesthetically pleasing and the 'bounce' of an app that needs attention is clear - even in full-screen mode (I tend to run almost everything in full screen).